The 1944 Australian Penny was minted at one of two mints.
Melbourne Mint (no mintmark - 2.45 million minted.
Perth Mint (mintmark = Y.) - 27.83 million minted.
The Australian Penny with the kangaroo on the reverse was first issued in 1938. There were some "Pattern" coins minted in 1937, but the very few of them that were minted, will all be in museums.
I will give you another chance at this question in case that is not what you meant. The reverse die was made in 1926, the coins were minted in 1927.
Nothing. Modified coins have no collector value.
All Australian Pennies minted from 1938 to 1964 inclusive feature a kangaroo on the reverse. The only Australian coins to feature wheat was the 1938 to 1964 inclusive, silver Threepence coins.
There were 4,337,200 Australian 1997 50 cent coins minted.
The rarest Australian coin minted for general circulation would be the 1930 Penny of which there were only 3,000 minted. It is currently esitmated that there are still about 1,500 of these still being traded in the market.
The 1922 Australian Penny does not have dots. The incredibly confusing system of dots above and/or below the scrolls was used as a mintmark to distinguish between coins minted at the Sydney Mint and the Melbourne Mint in 1919 and 1920.
All Australian Pennies minted from 1938 to 1964 inclusive feature a kangaroo on the reverse. The only Australian Coins to feature wheat was the 1938 to 1964 inclusive, silver Threepence coins.
Australian coins minted at the Melbourne Mint do not have a mintmark.
There were no Australian coins minted prior to 1911. With the possible exception of traders tokens (with the traders business name on them), there were no "Australian" coins minted prior to 1910. The only coins circulating in Australia prior to 1910 were British coins.
No 1937 Australian Pennies were minted for general circulation. There were 10 trial pattern coins minted with the usual King George VI on the obverse and kangaroo on the reverse. Possibly valued at $100,000 AUD. There were 8 trial pattern Uniface coins minted with "MODEL" on the obverse and kangaroo on the reverse. Possibly valued at $40,000 AUD. There was 1 trial pattern Uniface silver minted with "MODEL" on the obverse and kangaroo on the reverse. Possibly valued at $50,000 AUD.
Australian 1920 pennies were minted in both Melbourne and Sydney. On the reverse side underneath the word "PENNY", is a scroll. Coins minted in Melbourne will have a small dot under the scroll, coins minted in Sydney will have a small dot above the scroll. Some coins have no dot and could have been minted at either the Melbourne or Sydney Mints. The "no dots" coins are classified as rare. This means of determining the mint, only applies to 1920 pennies.